1. Field of the Invention
The present invention relates to an image forming apparatus to which a toner container provided with a wireless tag thereon is detachably mounted.
2. Description of the Related Art
Conventionally, image forming apparatuses such as a laser beam printer, a digital copier and a laser facsimile adopting an electrophotographic method have been used. In these image forming apparatuses, an image developing device develops an electrostatic latent image formed on a photoconductive drum by toner particles supplied from a toner cartridge. In the toner cartridge for supplying toner particles to the image developing device, there is provided a wireless tag (wireless IC tag) for storing information such as kinds and characteristics of the contained toner particles and the number of use of the toner cartridge. A communication unit provided in a main body of the image forming apparatus performs a wireless communication with the wireless tag so that information such as kinds and characteristics of toner particles and the number of use of the toner cartridge is transmitted to a controller of the main body (refer to Japanese Unexamined Patent Publication No. 2005-78100).
However, a distance within which the communication unit provided in the main body can perform the wireless communication with the wireless tag (hereinafter simply referred to as “communication distance”) is changed due to factors such as kinds and amount of toner particles in the toner cartridge or variation of used components. For example, when kinds and amount of toner particles are changed, metals (magnetic bodies) included in toner particles exert influence on a resonant frequency in a resonant circuit or the like in the wireless tag and thereby changes the communication distance (changes the strength of the wireless communication). Therefore, even when kinds and amount of toner particles are changed according to a passage of used time, it has been necessary to maintain a communication output at a level where the communication unit and the wireless tag are communicable. Therefore, there has been raised a problem that the communication output becomes excessively great according to conditions such as kinds and amount of toner particles and thereby causes a high level of unwanted radiation to be occurred.